azd-6244 and trametinib

New treatments for metastatic melanoma work through distinct mechanisms: enhancing the immune response and blocking cellular proliferation. Agents that enhance the immune response include ipilimumab, pembrolizumb, and nivolumab; agents that block cellular proliferation include vemurafenib, dabrafenib, trametinib, cobimetinib, binimetinib, and selumetinib. The translational impact of laboratory discoveries has revolutionized management of metastatic melanoma and enhanced the prognosis of affected patients.

Topics: Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Azetidines; Benzimidazoles; Humans; Imidazoles; Immunologic Factors; Indoles; Ipilimumab; Melanoma; Molecular Targeted Therapy; Nivolumab; Oximes; Piperidines; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Skin Neoplasms; Sulfonamides; Vemurafenib

The MAP-kinase pathway, consisting of the kinases RAS, RAF, MEK, and ERK, is crucial for cell proliferation, inhibition of apoptosis, and migration of cells. Direct inhibition of RAS is not yet possible, whereas inhibition of RAF is already established in malignant melanoma and under investigation in non-small-cell lung cancer (NSCLC). Due to their structure and function, the MEK proteins are attractive targets for cancer therapy and are also under investigation in NSCLC. We discuss strategies of targeting the RAS-RAF-MEK-ERK pathway with emphasis on MEK inhibition, either alone or in combination with other targets or conventional chemotherapy.

Topics: Benzimidazoles; Carcinoma, Non-Small-Cell Lung; Extracellular Signal-Regulated MAP Kinases; Humans; Lung Neoplasms; Molecular Targeted Therapy; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones

Targeting of oncogenic driver mutations with small-molecule inhibitors resulted in powerful treatment options for cancer patients in recent years. The RAS (rat sarcoma) pathway is among the most frequently mutated pathways in human cancer. Whereas targeting mutant Kirsten RAS (KRAS) remains difficult, mutant B rapidly accelerated fibrosarcoma (BRAF) kinase is an established drug target in cancer. Now data show that neuroblastoma RAS (NRAS) and even Harvey RAS (HRAS) mutations could be predictive markers for treatment with mitogen-activated protein kinase (MEK) inhibitors. This review discusses recent preclinical and clinical studies of MEK inhibitors in BRAF and RAS mutant cancer.

Topics: Animals; Azetidines; Benzamides; Benzimidazoles; Diphenylamine; Genes, ras; GTP Phosphohydrolases; Humans; Membrane Proteins; Mice; Mitogen-Activated Protein Kinases; Mutation; Neoplasms; Niacinamide; Piperidines; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; Signal Transduction; Sulfonamides

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Drug Discovery; Humans; Imidazoles; Indoles; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases; Molecular Targeted Therapy; Neoplasms; Oximes; Pyridones; Pyrimidinones; raf Kinases; Research; Sulfonamides; Vemurafenib

Malignant peripheral nerve sheath tumor (MPNST) is an aggressive form of soft-tissue sarcoma (STS) in children. Despite intensive therapy, relatively few children with metastatic and unresectable disease survive beyond three years. RAS pathway activation is common in MPNST, suggesting MEK pathway inhibition as a targeted therapy, but the impact on clinical outcome has been small to date.. The ability of MEK inhibitors to control MPNST growth cannot simply be predicted by serum drug levels or drug-induced changes in pERK expression. Tumor cell proliferation assessed by

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Benzimidazoles; Cell Proliferation; Fluorodeoxyglucose F18; Humans; Mice; Mice, Inbred NOD; Mice, SCID; Neurofibrosarcoma; Positron Emission Tomography Computed Tomography; Pyridones; Pyrimidinones; Radiopharmaceuticals; ras Proteins; Tissue Distribution; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

KRAS is one of the driver oncogenes in non-small-cell lung cancer (NSCLC) but remains refractory to current modalities of targeted pathway inhibition, which include inhibiting downstream kinase MEK to circumvent KRAS activation. Here, we show that pulsatile, rather than continuous, treatment with MEK inhibitors (MEKis) maintains T cell activation and enables their proliferation. Two MEKis, selumetinib and trametinib, induce T cell activation with increased CTLA-4 expression and, to a lesser extent, PD-1 expression on T cells in vivo after cyclical pulsatile MEKi treatment. In addition, the pulsatile dosing schedule alone shows superior anti-tumor effects and delays the emergence of drug resistance. Furthermore, pulsatile MEKi treatment combined with CTLA-4 blockade prolongs survival in mice bearing tumors with mutant Kras. Our results set the foundation and show the importance of a combinatorial therapeutic strategy using pulsatile targeted therapy together with immunotherapy to optimally enhance tumor delay and promote long-term anti-tumor immunity.

Topics: Animals; Benzimidazoles; Carcinoma, Non-Small-Cell Lung; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; CTLA-4 Antigen; Disease Models, Animal; Female; Humans; Lung Neoplasms; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Programmed Cell Death 1 Receptor; Protein Kinase Inhibitors; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; Survival Rate; T-Lymphocytes

To analyze the activity of mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinases/mechanistic target of rapamycin (PI3K/mTOR) pathways in benign and malignant conjunctival melanocytic proliferations and explore whether specific inhibitors can suppress growth of conjunctival melanoma (CJM) cells.. The presence of a BRAF V600E mutation and activation of ERK, MEK, S6, and AKT were assessed with immunohistochemistry in 35 conjunctival nevi and 31 melanomas. Three CJM cell lines were used: CRMM1, carrying the BRAF V600E mutation; CRMM2, harboring the NRAS Q61L mutation; and T1527A, with a BRAF G466E mutation. WST-1 assays were performed with a BRAF inhibitor (vemurafenib), two MEK inhibitors (trametinib, selumetinib), a PI3K inhibitor (pictilisib), and a dual PI3K/mTOR inhibitor (dactolisib). The phosphorylation of ERK, MEK, and S6 were tested with western blots and apoptosis with cleaved caspase-3 immunostaining.. A BRAF V600E mutation was detected in 42.6% of nevi and in 35.5% of CJM. MEK and ERK activation were higher in CJM, occurring in 62.9% and 45.7% of the nevi and 90.3% and 96.8% of the CJM, respectively. There was also a significant increase in S6 activation in CJM (90.3%) compared with the nevi (20%). CRMM1 was sensitive to trametinib and the PI3K inhibitors but only marginally to vemurafenib. CRMM2 was moderately sensitive to pictilisib, whereas T1527A was resistant to all drugs tested.. The MAPK pathway activity in CJM is increased, not only as a consequence of the BRAF V600E mutation. Targeted therapy may be useful for patients with CJM, especially those with activating BRAF mutations, whereas NRAS-mutated melanomas are relatively resistant.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Benzimidazoles; Blotting, Western; Conjunctival Neoplasms; Female; Fluorescent Antibody Technique, Indirect; Humans; Imidazoles; Indazoles; Male; Melanoma; Middle Aged; Mitogen-Activated Protein Kinases; Molecular Targeted Therapy; Phosphatidylinositol 3-Kinases; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Quinolines; Sulfonamides; TOR Serine-Threonine Kinases; Tumor Cells, Cultured

Mutations in KRAS are frequent in human cancer, yet effective targeted therapeutics for these cancers are still lacking. Attempts to drug the MEK kinases downstream of KRAS have had limited success in clinical trials. Understanding the specific genomic vulnerabilities of KRAS-driven cancers may uncover novel patient-tailored treatment options.. We first searched for synthetic lethal (SL) genetic interactions with mutant RAS in yeast with the ultimate aim to identify novel cancer-specific targets for therapy. Our method used selective ploidy ablation, which enables replication of cancer-specific gene expression changes in the yeast gene disruption library. Second, we used a genome-wide CRISPR/Cas9-based genetic screen in KRAS mutant human colon cancer cells to understand the mechanistic connection between the synthetic lethal interaction discovered in yeast and downstream RAS signaling in human cells.. We identify loss of the endoplasmic reticulum (ER) stress sensor IRE1 as synthetic lethal with activated RAS mutants in yeast. In KRAS mutant colorectal cancer cell lines, genetic ablation of the human ortholog of IRE1, ERN1, does not affect growth but sensitizes to MEK inhibition. However, an ERN1 kinase inhibitor failed to show synergy with MEK inhibition, suggesting that a non-kinase function of ERN1 confers MEK inhibitor resistance. To investigate how ERN1 modulates MEK inhibitor responses, we performed genetic screens in ERN1 knockout KRAS mutant colon cancer cells to identify genes whose inactivation confers resistance to MEK inhibition. This genetic screen identified multiple negative regulators of JUN N-terminal kinase (JNK) /JUN signaling. Consistently, compounds targeting JNK/MAPK8 or TAK1/MAP3K7, which relay signals from ERN1 to JUN, display synergy with MEK inhibition.. We identify the ERN1-JNK-JUN pathway as a novel regulator of MEK inhibitor response in KRAS mutant colon cancer. The notion that multiple signaling pathways can activate JUN may explain why KRAS mutant tumor cells are traditionally seen as highly refractory to MEK inhibitor therapy. Our findings emphasize the need for the development of new therapeutics targeting JUN activating kinases, TAK1 and JNK, to sensitize KRAS mutant cancer cells to MEK inhibitors.

Topics: Antineoplastic Agents; Benzimidazoles; Cell Line, Tumor; Colonic Neoplasms; Endoplasmic Reticulum Stress; Endoribonucleases; HEK293 Cells; Humans; MAP Kinase Kinase Kinases; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins c-jun; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; Unfolded Protein Response; Yeasts

Diverse pathways drive resistance to BRAF/MEK inhibitors in BRAF-mutant melanoma, suggesting that durable control of resistance will be a challenge. By combining statistical modeling of genomic data from matched pre-treatment and post-relapse patient tumors with functional interrogation of >20 in vitro and in vivo resistance models, we discovered that major pathways of resistance converge to activate the transcription factor, c-MYC (MYC). MYC expression and pathway gene signatures were suppressed following drug treatment, and then rebounded during progression. Critically, MYC activation was necessary and sufficient for resistance, and suppression of MYC activity using genetic approaches or BET bromodomain inhibition was sufficient to resensitize cells and delay BRAFi resistance. Finally, MYC-driven, BRAFi-resistant cells are hypersensitive to the inhibition of MYC synthetic lethal partners, including SRC family and c-KIT tyrosine kinases, as well as glucose, glutamine, and serine metabolic pathways. These insights enable the design of combination therapies that select against resistance evolution.

Topics: Antineoplastic Agents, Hormonal; Benzimidazoles; Cell Line, Tumor; Estradiol; Evolution, Molecular; Female; Fulvestrant; Humans; Imidazoles; Indoles; Male; Melanoma; Oximes; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-myc; Pyridones; Pyrimidinones; Quinolines; Signal Transduction; Sulfonamides

LKB1 is a commonly mutated tumor suppressor in non-small cell lung cancer that exerts complex effects on signal transduction and transcriptional regulation. To better understand the downstream impact of loss of functional LKB1, we developed a transcriptional fingerprint assay representing this phenotype. This assay was predictive of LKB1 functional loss in cell lines and clinical specimens, even those without detected sequence alterations in the gene. In silico screening of drug sensitivity data identified putative LKB1-selective drug candidates, revealing novel associations not apparent from analysis of LKB1 mutations alone. Among the candidates, MEK inhibitors showed robust association with signature expression in both training and testing datasets independent of RAS/RAF mutations. This susceptibility phenotype is directly altered by RNA interference-mediated LKB1 knockdown or by LKB1 re-expression into mutant cell lines and is readily observed in vivo using a xenograft model. MEK sensitivity is dependent on LKB1-induced changes in AKT and FOXO3 activation, consistent with genomic and proteomic analyses of LKB1-deficient lung adenocarcinomas. Our findings implicate the MEK pathway as a potential therapeutic target for LKB1-deficient cancers and define a practical NanoString biomarker to identify functional LKB1 loss. Cancer Res; 77(1); 153-63. ©2016 AACR.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; AMP-Activated Protein Kinase Kinases; Animals; Benzimidazoles; Biomarkers, Tumor; Drug Resistance, Neoplasm; Female; Heterografts; Humans; Immunoblotting; Lung Neoplasms; MAP Kinase Kinase Kinases; MAP Kinase Signaling System; Mice; Mice, Inbred NOD; Mice, SCID; Oligonucleotide Array Sequence Analysis; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Pyridones; Pyrimidinones; Transcriptome

It has been a challenge to identify liver tumor suppressors or oncogenes due to the genetic heterogeneity of these tumors. We performed a genome-wide screen to identify suppressors of liver tumor formation in mice, using CRISPR-mediated genome editing.. We identified 4 candidate liver tumor suppressor genes not previously associated with liver cancer (Nf1, Plxnb1, Flrt2, and B9d1). CRISPR-mediated knockout of Nf1, a negative regulator of RAS, accelerated liver tumor formation in mice. Loss of Nf1 or activation of RAS up-regulated the liver progenitor cell markers HMGA2 and SOX9. RAS pathway inhibitors suppressed the activation of the Hmga2 and Sox9 genes that resulted from loss of Nf1 or oncogenic activation of RAS. Knockdown of HMGA2 delayed formation of xenograft tumors from cells that expressed oncogenic RAS. In human HCCs, low levels of NF1 messenger RNA or high levels of HMGA2 messenger RNA were associated with shorter patient survival time. Liver cancer cells with inactivation of Plxnb1, Flrt2, and B9d1 formed more tumors in mice and had increased levels of mitogen-activated protein kinase phosphorylation.. Using a CRISPR-based strategy, we identified Nf1, Plxnb1, Flrt2, and B9d1 as suppressors of liver tumor formation. We validated the observation that RAS signaling, via mitogen-activated protein kinase, contributes to formation of liver tumors in mice. We associated decreased levels of NF1 and increased levels of its downstream protein HMGA2 with survival times of patients with HCC. Strategies to inhibit or reduce HMGA2 might be developed to treat patients with liver cancer.

Topics: Animals; Benzimidazoles; Blotting, Western; Butadienes; Carcinoma, Hepatocellular; Cell Line, Tumor; CRISPR-Cas Systems; Cytoskeletal Proteins; DNA, Neoplasm; Enzyme Inhibitors; Gene Expression Regulation, Neoplastic; Genes, Neurofibromatosis 1; Genome-Wide Association Study; Hepatocytes; High-Throughput Nucleotide Sequencing; HMGA Proteins; HMGA2 Protein; Humans; Immunohistochemistry; Liver Neoplasms; Liver Neoplasms, Experimental; Membrane Glycoproteins; Mice; Mice, Knockout; Mice, Nude; Mitogen-Activated Protein Kinases; Nerve Tissue Proteins; Niacinamide; Nitriles; Phenylurea Compounds; Prognosis; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-myc; Pyridones; Pyrimidinones; ras Proteins; Real-Time Polymerase Chain Reaction; Receptors, Cell Surface; Sequence Analysis, DNA; Sorafenib; Survival Analysis; Tumor Suppressor Protein p53; Tumor Suppressor Proteins

KRAS mutations are an established predictor of lack of response to EGFR-targeted therapies in patients with metastatic colorectal cancer (mCRC). However, little is known about the role of the rarer NRAS mutations as a mechanism of primary resistance to the anti-EGFR monoclonal antibody cetuximab in wild-type KRAS mCRC. Using isogenic mCRC cells with a heterozygous knock-in of the NRAS activating mutation Q61K, we aimed to elucidate the mechanism(s) by which mutant NRAS blocks cetuximab from inhibiting mCRC growth. NRASQ61K/+ cells were refractory to cetuximab-induced growth inhibition. Pathway-oriented proteome profiling revealed that cetuximab-unresponsive ERK1/2 phosphorylation was the sole biomarker distinguishing cetuximab-refractory NRASQ61K/+ from cetuximab-sensitive NRAS+/+ cells. We therefore employed four representative MEK1/2 inhibitors (binimetinib, trametinib, selumetinib, and pimasertib) to evaluate the therapeutic value of MEK/ERK signaling in cetuximab-refractory NRAS mutation-induced mCRC. Co-treatment with an ineffective dose of cetuximab augmented, up to more than 1,300-fold, the cytotoxic effects of pimasertib against NRASQ61K/+ cells. Simultaneous combination of MEK1/2 inhibitors with cetuximab resulted in extremely high and dose-dependent synthetic lethal effects, which were executed, at least in part, by exacerbated apoptotic cell death. Dynamic monitoring of real-time cell growth rates confirmed that cetuximab synergistically sensitized NRASQ61K/+ cellsto MEK1/2 inhibition. Our discovery of a synthetic lethal interaction of cetuximab in combination with MEK1/2 inhibition for the NRAS mutant subgroup of mCRC underscores the importance of therapeutic intervention both in the MEK-ERK and EGFR pathways to achieve maximal therapeutic efficacy against NRAS-mutant mCRC tumors.

Topics: Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Benzimidazoles; Cell Line, Tumor; Cell Proliferation; Cetuximab; Colorectal Neoplasms; Dose-Response Relationship, Drug; Drug Resistance, Neoplasm; Drug Synergism; ErbB Receptors; GTP Phosphohydrolases; Humans; MAP Kinase Kinase 1; MAP Kinase Kinase 2; Membrane Proteins; Mutation; Niacinamide; Phosphorylation; Protein Kinase Inhibitors; Proteomics; Pyridones; Pyrimidinones; Signal Transduction; Transfection

MEK inhibitors are being evaluated in clinical trials for treatment of different malignant neoplasms; trametinib dimethyl sulfoxide was approved by the US Food and Drug Administration for melanoma in 2013. We present 3 cases of patients receiving MEK inhibitors who developed an atypical eruption.. Three patients who were receiving different MEK inhibitors (selumetinib, cobimetinib, and trametinib) developed an eruption, all associated with unique duskiness. Drug hypersensitivity was confirmed by histopathologic testing in 2 of the 3 cases. The skin eruption responded well to corticosteroids and did not recur when treatment with the MEK inhibitor was restarted in 2 of the patients.. The typical skin reaction associated with MEK inhibitors is a papulopustular eruption. To our knowledge, the dusky erythema that occurred in the 3 patients described here has not previously been reported for this drug class.

Topics: Adult; Azetidines; Benzimidazoles; Drug Eruptions; Erythema; Female; Glucocorticoids; Humans; Male; Melanoma; Middle Aged; Mitogen-Activated Protein Kinase Kinases; Piperidines; Protein Kinase Inhibitors; Pyridones; Pyrimidinones; Skin Neoplasms

With more than 1 million deaths worldwide every year, lung cancer remains an area of unmet need. Accessible human in vitro 3D tissue models are required to improve preclinical predictivity. OncoCilAir™ is a new in vitro model of Non Small Cell Lung Cancer which combines a reconstituted human airway epithelium, human lung fibroblasts and lung adenocarcinoma cell lines. Remarkably, we found that in this 3D microenvironment tumour cells expand by forming nodules, mimicking a human lung cancer feature. OncoCilAir™ mutated for KRAS and expressing the green fluorescent protein were used to test the antitumour potential of the investigational MEK inhibitors selumetinib and trametinib. As primary endpoint, changes in tumour size were assessed by fluorescence measurements. Tumours showed a reduced growth in response to the MEK inhibitors, but halting the selumetinib dosing resulted in tumour relapse. Importantly, toxicity study on the normal part of the cultures revealed that the airway epithelium integrity was also affected by anticancer drug treatments. These results highlight the possibility to assess simultaneously drug efficacy, drug side-effect and tumour recurrence within a single culture model. OncoCilAir™ heralds a new generation of integrated in vitro tumour models that should be valuable tools for drug development, while reducing animal testing.

Topics: Benzimidazoles; Cell Proliferation; Cells, Cultured; Drug Screening Assays, Antitumor; Epithelial Cells; Fibroblasts; Humans; Lung; Lung Neoplasms; Models, Biological; Protein Kinase Inhibitors; Pyridones; Pyrimidinones; Tumor Microenvironment

Uveal melanoma patients with metastatic disease usually die within one year, emphasizing an urgent need to develop new treatment strategies for this cancer. MEK inhibitors improve survival in cutaneous melanoma patients but show only modest efficacy in metastatic uveal melanoma patients. In this study, we screened for growth factors that elicited resistance in newly characterized metastatic uveal melanoma cell lines to clinical-grade MEK inhibitors, trametinib and selumetinib. We show that neuregulin 1 (NRG1) and hepatocyte growth factor (HGF) provide resistance to MEK inhibition. Mechanistically, trametinib enhances the responsiveness to NRG1 and sustained HGF-mediated activation of AKT. Individually targeting ERBB3 and cMET, the receptors for NRG1 and HGF, respectively, overcome resistance to trametinib provided by these growth factors and by conditioned medium from fibroblasts that produce NRG1 and HGF. Inhibition of AKT also effectively reverses the protective effect of NRG1 and HGF in trametinib-treated cells. Uveal melanoma xenografts growing in the liver in vivo and a subset of liver metastases of uveal melanoma patients express activated forms of ERBB2 (the coreceptor for ERBB3) and cMET. Together, these results provide preclinical evidence for the use of MEK inhibitors in combination with clinical-grade anti-ERBB3 or anti-cMET monoclonal antibodies in metastatic uveal melanoma.

Topics: Animals; Benzimidazoles; Cell Line, Tumor; Drug Resistance, Neoplasm; Hepatocyte Growth Factor; Humans; MAP Kinase Kinase Kinases; Melanoma; Mice; Neuregulin-1; Proto-Oncogene Proteins c-met; Pyridones; Pyrimidinones; Receptor, ErbB-3; Tumor Cells, Cultured; Uveal Neoplasms; Xenograft Model Antitumor Assays

The aim of combination drug treatment in cancer therapy is to improve response rate and to decrease the probability of the development of drug resistance. Preferably, drug combinations are synergistic rather than additive, and, ideally, drug combinations work synergistically only in cancer cells and not in non-malignant cells. We have developed a workflow to identify such targeted synergies, and applied this approach to selectively inhibit the proliferation of cell lines with mutations in genes that are difficult to modulate with small molecules. The approach is based on curve shift analysis, which we demonstrate is a more robust method of determining synergy than combination matrix screening with Bliss-scoring. We show that the MEK inhibitor trametinib is more synergistic in combination with the BRAF inhibitor dabrafenib than with vemurafenib, another BRAF inhibitor. In addition, we show that the combination of MEK and BRAF inhibitors is synergistic in BRAF-mutant melanoma cells, and additive or antagonistic in, respectively, BRAF-wild type melanoma cells and non-malignant fibroblasts. This combination exemplifies that synergistic action of drugs can depend on cancer genotype. Next, we used curve shift analysis to identify new drug combinations that specifically inhibit cancer cell proliferation driven by difficult-to-drug cancer genes. Combination studies were performed with compounds that as single agents showed preference for inhibition of cancer cells with mutations in either the CTNNB1 gene (coding for β-catenin), KRAS, or cancer cells expressing increased copy numbers of MYC. We demonstrate that the Wnt-pathway inhibitor ICG-001 and trametinib acted synergistically in Wnt-pathway-mutant cell lines. The ERBB2 inhibitor TAK-165 was synergistic with trametinib in KRAS-mutant cell lines. The EGFR/ERBB2 inhibitor neratinib acted synergistically with the spindle poison docetaxel and with the Aurora kinase inhibitor GSK-1070916 in cell lines with MYC amplification. Our approach can therefore efficiently discover novel drug combinations that selectively target cancer genes.

Topics: Antineoplastic Combined Chemotherapy Protocols; Aza Compounds; Benzimidazoles; beta Catenin; Cell Line, Tumor; Cell Proliferation; Humans; Imidazoles; Indazoles; Indoles; Melanoma; Molecular Targeted Therapy; Mutation; Oxazoles; Oximes; Proto-Oncogene Proteins B-raf; Proto-Oncogene Proteins c-myc; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; Quinolines; Sulfonamides; Triazoles; Vemurafenib

BRAF-mutant melanoma can be successfully treated by BRAF kinase inhibitors (BRAFi) and MEK kinase inhibitors (MEKi). However, the administration of BRAFi followed by MEKi did not generate promising response rate (RR). The purpose of this investigation was to evaluate the time to progression (TTP) with a mitogen-activated protein kinase (MAPK) pathway upstream inhibition strategy in BRAF mutated melanoma patients. BRAF mutation positive metastatic melanoma patients were identified within the Dermatology Cooperative Oncology Group (DeCOG) network and were treated first with a MEKi and upon progression with a selective BRAFi. A total of 23 melanoma patients (six females, 17 males, aged 47-80 years) were retrospectively analysed for TTP. The total median TTP was 8.9 months. The median TTP for MEKi was 4.8 (1.2-23.2) and subsequent for BRAFi 4.5 (1.2-15.7) months, respectively. A higher RR for MEKi (39%, nine partial responses and 0 complete responses) than previously reported was observed. Our analysis suggests that the reversed inhibition of the MAPK pathway is feasible in BRAF mutated melanoma. The median TTP (8.9 months) is close to the promising BRAF- and MEKi combination therapy (median progression-free survival (PFS) 9.4 months). The total treatment duration of the MAPK inhibition when a MEKi is administered first is similar compared to the reversed sequence, but TTP shifts in favour to the MEKi. This approach is feasible with reasonable tolerability. This clinical investigation encourages further studies in prospective clinical trials to define the optimal treatment schedule for the MAPK pathway inhibition and should be accompanied by molecular monitoring using repeated biopsies.

Topics: Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Benzimidazoles; Disease Progression; Disease-Free Survival; Feasibility Studies; Female; Humans; Imidazoles; Indoles; Male; MAP Kinase Signaling System; Melanoma; Middle Aged; Mitogen-Activated Protein Kinases; Mutation; Outcome Assessment, Health Care; Oximes; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Retrospective Studies; Sulfonamides; Time Factors; Vemurafenib

We sought to determine the frequency and clinical characteristics of patients with lung cancer harboring NRAS mutations. We used preclinical models to identify targeted therapies likely to be of benefit against NRAS-mutant lung cancer cells.. We reviewed clinical data from patients whose lung cancers were identified at six institutions or reported in the Catalogue of Somatic Mutations in Cancer (COSMIC) to harbor NRAS mutations. Six NRAS-mutant cell lines were screened for sensitivity against inhibitors of multiple kinases (i.e., EGFR, ALK, MET, IGF-1R, BRAF, PI3K, and MEK).. Among 4,562 patients with lung cancers tested, NRAS mutations were present in 30 (0.7%; 95% confidence interval, 0.45%-0.94%); 28 of these had no other driver mutations. 83% had adenocarcinoma histology with no significant differences in gender. While 95% of patients were former or current smokers, smoking-related G:C>T:A transversions were significantly less frequent in NRAS-mutated lung tumors than KRAS-mutant non-small cell lung cancer [NSCLC; NRAS: 13% (4/30), KRAS: 66% (1772/2733), P < 0.00000001]. Five of 6 NRAS-mutant cell lines were sensitive to the MEK inhibitors, selumetinib and trametinib, but not to other inhibitors tested.. NRAS mutations define a distinct subset of lung cancers (∼1%) with potential sensitivity to MEK inhibitors. Although NRAS mutations are more common in current/former smokers, the types of mutations are not those classically associated with smoking.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Benzimidazoles; Cell Line, Tumor; DNA Mutational Analysis; Female; Gene Frequency; Genetic Association Studies; GTP Phosphohydrolases; Humans; Inhibitory Concentration 50; Lung Neoplasms; Male; Membrane Proteins; Middle Aged; Mutation, Missense; Protein Kinase Inhibitors; Proto-Oncogene Proteins; Proto-Oncogene Proteins p21(ras); Pyridones; Pyrimidinones; ras Proteins

MEK1/2 inhibitors such as AZD6244 are in clinical trials for the treatment of multiple cancers, including breast cancer. Targeted kinase inhibition can induce compensatory kinome changes, rendering single therapeutic agents ineffective. To identify target proteins to be used in a combinatorial approach to inhibit tumor cell growth, we used a novel strategy that identified microRNAs (miRNAs) that synergized with AZD6244 to inhibit the viability of the claudin-low breast cancer cell line MDA-MB-231. Screening of a miRNA mimic library revealed the ability of miR-9-3p to significantly enhance AZD6244-induced extracellular signal-regulated kinase inhibition and growth arrest, while miR-9-3p had little effect on growth alone. Promoter methylation of mir-9 genes correlated with low expression of miR-9-3p in different breast cancer cell lines. Consistent with miR-9-3p having synthetic enhancer tumor suppressor characteristics, miR-9-3p expression in combination with MEK inhibitor caused a sustained loss of c-MYC expression and growth inhibition. The β1 integrin gene (ITGB1) was identified as a new miR-9-3p target, and the growth inhibition seen with small interfering RNA knockdown or antibody blocking of ITGB1 in combination with MEK inhibitor phenocopied the growth inhibition seen with miR-9-3p plus AZD6244. The miRNA screen led to identification of a druggable protein, ITGB1, whose functional inhibition synergizes with MEK inhibitor.

Topics: 3' Untranslated Regions; Benzimidazoles; Breast Neoplasms; Cell Movement; Cell Proliferation; Claudins; Enzyme Inhibitors; Epigenesis, Genetic; Female; Gene Expression Regulation, Neoplastic; Genes, myc; Humans; Integrin beta1; MAP Kinase Kinase Kinases; MicroRNAs; Pyridones; Pyrimidinones